A keyboard device for use in electronic apparatus such as a personal computer has a configuration in which a plurality of push button devices (key switches) are arranged. The keyboard device is generally configured to include key caps vertically movable on a base plate. Some keyboard devices of this type are configured to include a guide mechanism having a pantograph structure provided between the base plate and the key caps to guide vertical movement of the key caps (see Japanese Patent Application Laid-Open No. 2015-141868).